Question on frame strength on 31' Sovereign

[hinz57]

All,

On the history link, there is a reference to the frame being made lighter at some point, apparently by the Beatrice Co. Also the rear bath being an issue due to weight? I would appreciate any comments on this issue. Are the 68 and older models structurely superior? If a person buys a 70's model with rear bedroom, is the frame strong enough?

All input greatly appreciated!

hinz57

[overlander63]

Our sovereign's frame is not as strong as you might expect. Instead of 5" box channel (standard fare starting in the '80's), it has a 5" C channel, with a 5" box for about the first 3-4 feet. The box channel area is not that great, either, it has holes punched in it every few inches. The frame broke just aft of the box channel area, and the trailer suffers from rear sag.
The reason ours is so bad, is because it spent most of its life near salt water, which rusted the structural steel. The rear bath models tend to suffer more from sag because there is an access compartment door in the back to leak rainwater, plus there are cutouts of the rear floor where it attaches to the floor channel, as well as the additional weight of the holding tanks, tub, toilet, etc.
The rear bedroom models are "better", because the sag is easier to fix without all the bathroom stuff in the way.

[bryanl]

Beatrice inherited a frame size reduction made to conserve weight.

The problem is not weight so much as vibration. If the floor gets weak, it can separate from the shell and the rear can droop. The frame and shell work together structurally but only if properly attached.

This is why Andy is so hep on wheel balancing, especially for the 70's trailers. It is the bouncing and vibration that can separate frame and shell and stimulate separation.

[hinz57]

Thanks guys,

Good information. Can I assume that all Sovereign models have about the same frame, even if you go back to the older 30 foot models? Also there are unlimited horror stories on this forum about frame damage. What is the likely hood of finding any Sovereign without frame damage.

Thanks in advance,
hinz57

[Lumatic]

Yes the 70s AS had shorter frames. And, yes, the longer Airstreams are more prone to rear end sag or separation. My take is if an AS was well maintained this issue should not have caused any problems. A good inspection can quickly determine this. You should find a lot of more information if you search past threads on the subject. Only the trailers of the "Beatrice Years" (mainly the 70s) had these frames. And all models of these years had the same type of frame not just Sovereigns.

[ArtStream]

At the WBCCI International in Bozeman, MT there were 100's of trailers, many from the 70's and 80's.

I payed particular attention to front and rear separation.

My informal eyeball reveled almost every rig larger that 28 foot showed some sign of front or rear separation. I noticed more front separation on 80's models. In some cases cracks above the door had developed, others looked like old shoes which were loosing the front of there soles.

[Lumatic]

Originally Posted by ArtStream

At the WBCCI International in Bozeman, MT there were 100's of trailers, many from the 70's and 80's.

I payed particular attention to front and rear separation.

I noticed more front separation on 80's models.

This is the first I have heard of a front separation problem. Are the 80s models prone to this as the 70s are prone to rear separation?

[ArtStream]

I'm sorry to say that since they removed the hold-down support plate in the front and removed vertical supports to make room for the battery compartments, 90's and 2000's are experiencing front end separation

[bryanl]

gheesh. to hear this kind of talk you'd think all AS trailers over a few years old were heaps of scrap ... Stop to think about the idea that hundred of trailers with severe structural defects drove thousands of miles to show up at a rally - seems to be a bit of dissonance in this set of observations.

I have an Ambassador and a Sovereign of 1975 vintage in the driveway and neither has any frame separation problem.

I have seen a 72 with rear sep and a 78 that had the dog ears repair evidence. The latter had been to Alaska twice. Both showed evidence of significant and severe use.

Do check any trailer you are thinking about purchasing for evidence of such flaws but I don't think you should be paranoid.

[hinz57]

All,

Thanks for the info. I am new to AS and simply attempting to learn and understand what issues exist so that I can make an informed choice. I have been searching this site and others. I have found considerable reference to these seperation issues and want to avoid, if possible, making a purchase that requires lots of extra labor and funds. Not being paranoid at all. Just want to be educated.

Regards, hinz57

[garry]

Majority of the problems are with the rear bath units.

There are two separate problems one is rear separation and and be seen above the rear bumper (open space above the bumper) the other is the frame bending that can be seen as the skin bending at the rear wheel area.

There is a bolt on frame strengthening kit available that is best put on before you have a problem. The rear end separation fix is more complicated.

Garry

[Inland RV Center, In]

Originally Posted by hinz57

All,

On the history link, there is a reference to the frame being made lighter at some point, apparently by the Beatrice Co. Also the rear bath being an issue due to weight? I would appreciate any comments on this issue. Are the 68 and older models structurely superior? If a person buys a 70's model with rear bedroom, is the frame strong enough?

All input greatly appreciated!

hinz57

The strength of an Airstream trailer, is not in the frame, but it "is" in the shell.

The shell holds the frame up. The frame "DOES NOT" hold the shell up.

Obviously then, the manner in which the shell is attached to the frame, is serious business.

Beefing the frame up to carry addition weight, is a complete waste, "UNLESS" additional hold down strength is installed.

Adding the frame beef up kit at the axles, does nothing more than beef up that area, PERIOD. It does not correct rear end sag, nor will it prevent it.

Hold down plates, properly installed at the front and rear, are extremely important, since it is "they" that hold the frame to the shell.

It's sort of like a wing on an aircraft. The wing can be super strong, but if it's not attached to the fuselage properly, kiss it goodby.

Andy

[Kevin245]

Originally Posted by Inland RV Center, In

It's sort of like a wing on an aircraft. The wing can be super strong, but if it's not attached to the fuselage properly, kiss it goodby.

Andy

Kind of puts things into perspective. Thanks Andy!

[DavidsonOverlander]

Originally Posted by Inland RV Center, In

Hold down plates, properly installed at the front and rear, are extremely important, since it is "they" that hold the frame to the shell.
Andy

Thanks Andy!
Could you explain what these additional hold down plates look like and where they should be located? Pictures would be great if anyone has some.

Grant

[HiHoAgRV]

Originally Posted by Lumatic

Yes the 70s AS had shorter frames. ..And all models of these years had the same type of frame not just Sovereigns.

Quite a few threads cover the smaller frame of the '70's, dropping to 4" then as small as a reported 3".
My 29' has a 5" frame and stiffening plates that seem to have been installed straight from the beginning. As of now we have no rear seperation even with our extensive use. All of the other '70's AS's I have seen (not a huge number) also have the full size frame.

[Inland RV Center, In]

Originally Posted by DavidsonOverlander

Thanks Andy!
Could you explain what these additional hold down plates look like and where they should be located? Pictures would be great if anyone has some.

Grant

Hold down plates are at the front and rear of the shell.

Their purpose is to hold the frame to the shell.

The front plate is obvious on the older trailers, with 3 horizontal rows of rivets.

We increase that to 5 rows.

The rear plate is smaller, since the rear access door is in the way. But again, the more rivets, the better the hold down.

Also at the rear, installing a bracket on the outside of the frame, underneath the banana wraps, adds considerably to the holding strength. Bolts go thru a steel plate placed in the floor channel, the floor channel, the floor, and then thru the new plate.

Using "fender" washers in that area helps too.

Andy